TITLE: How is $\epsilon_0$ countable?
QUESTION [14 upvotes]: In Wikipedia, it says that any epsilon number with the index that is countable is countable. How is it? Out of all those numbers, I especially want to know why $\epsilon_0$ is countable.
Thanks.

REPLY [2 votes]: Vsauce introduces really well the subject. https://www.youtube.com/watch?v=SrU9YDoXE88